Brake Master Cylinder

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rayofleamington
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Post by rayofleamington »

my pedal is firm, and doesn't go down to the floor when pressed hard for a while.
If it leaks on its own but you have a firm pedal that doesn't slowly sink, then I can't see how it will be the T-piece. It really seems to be a leaking secondary seal (the one that is meant to stop the reservoir fluid leaking out of the bore). Normally they leak both ways i.e. allows fluid out and lets air in - This will give the bubble when you press the pedal, but I suppose it is possible that it could leak without letting air in.
Onne
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Post by Onne »

I have ordered a BMC set. Which will come with new bolts and nuts, copper washers etc.

I don't actually know which one I have, but I have purchased the 1098 one, because of my big brakes up front.
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rayofleamington
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Post by rayofleamington »

I don't actually know which one I have, but I have purchased the 1098 one, because of my big brakes up front.
I was told that the early ones are not easy to get anyway!
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Post by Onne »

I think there are only 2 sorts, the big bore for the early ones, with the 7" drums, and the smaller bore for the big braked Minors
Onne van der S. MMOCno 60520 Moderator
2dr 1971 White DAF 55 (with hopefully a 1600cc engine soon)
2dr 1973 Bergina (DAF 44)
2dr Estate 1975 DAF 46 in red
2dr saloon 1972 DAF 44 in Mimosa
Onne
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Post by Onne »

I replaced it today. All sorted within two hours, no messing with the torsion bar, the bolts were already t'other way round.

I inspected the BMC, the bore was knackered, and there was a lot of sand in the resevoir. Or rusty crud.

It's now all nice and working again!
Onne van der S. MMOCno 60520 Moderator
2dr 1971 White DAF 55 (with hopefully a 1600cc engine soon)
2dr 1973 Bergina (DAF 44)
2dr Estate 1975 DAF 46 in red
2dr saloon 1972 DAF 44 in Mimosa
bmcecosse
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Post by bmcecosse »

Well done - result!
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Onne
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Post by Onne »

Indeed, nice to have brakes I can rely on
Onne van der S. MMOCno 60520 Moderator
2dr 1971 White DAF 55 (with hopefully a 1600cc engine soon)
2dr 1973 Bergina (DAF 44)
2dr Estate 1975 DAF 46 in red
2dr saloon 1972 DAF 44 in Mimosa
Chris Morley
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Post by Chris Morley »

Glad to hear you got the problem sorted Onne. If you aren't sure if a clear liquid is brake fluid, just mop some up in a tissue and sniff it. The smell of brake fluid is pretty obvious.
Chris
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Kevin
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Post by Kevin »

and there was a lot of sand in the resevoir.
Obviously used as a Beach Buggy in the past then :wink:
Cheers

Kevin
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Stig
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Post by Stig »

Kevin wrote:
and there was a lot of sand in the resevoir.
Obviously used as a Beach Buggy in the past then :wink:
I thought it was because of the drought!
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Post by Onne »

well, it's not the hills that have the sand, thats for sure!
Onne van der S. MMOCno 60520 Moderator
2dr 1971 White DAF 55 (with hopefully a 1600cc engine soon)
2dr 1973 Bergina (DAF 44)
2dr Estate 1975 DAF 46 in red
2dr saloon 1972 DAF 44 in Mimosa
cliff
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Post by cliff »

Onne wrote:I replaced it today. All sorted within two hours, no messing with the torsion bar, the bolts were already t'other way round.
i've just asked a similar question on another thread and was advised that the bolts should be as originally intended as the nuts can wear a groove into the torsion bar with dire consquences, just thought i'd mention it.
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Post by bigginger »

'tis true, unless you have thinner nuts on them and pack the heads out with washers. A bit more work, but you only have to do it once.
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Post by Onne »

that is the way I have done it. Torsion bar is not near it.

Onne
Onne van der S. MMOCno 60520 Moderator
2dr 1971 White DAF 55 (with hopefully a 1600cc engine soon)
2dr 1973 Bergina (DAF 44)
2dr Estate 1975 DAF 46 in red
2dr saloon 1972 DAF 44 in Mimosa
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